Articulated concrete column form with novel corner fastening device

ABSTRACT

A quick-release fastening device for fixedly but releasably securing together the outer end edges of two pivotally connected right angle sections of a concrete column form.

United States Patent 11 1 Plough Nov. 4, 1975 ARTICULATED CONCRETE COLUMN 1,842,684 1/1932 Markham 249/219 R FORM W NOVEL CORNER FASTENING 1,871,919 8/1932 Schubert 249/166 DEVICE 3,169,294 2/1965 Bonin et a]. 249/196 3,204,918 9/1965 Bonin et a1. 249/196 [75] Inventor: Russell H. Plough, Chicago, 111. 3,357,673 12/1967 Williams 249/194 [73] Assignee: Symons Corporation, Des Plaines,

Pn'mary ExaminerFrancis S. Husar Assistant Examiner-John McQuade F [22] fled Mar U74 Attorney, Agent, or FirmNorman H. Gerlach [21] Appl. N0.: 454,721

[52 US. Cl 249/48; 249/194; 249/219 R ABSTRACT [51] Int. Cl. E04G 13/02 53 Field f Search 249/48 194 219 R, 47 A quick-release fastening device for fixedly but releas- 249/192 ]93, 196, 166 ably securing together the outer end edges of two pivotally connected right angle sections of a concrete 001- [56] References Cited form- UNITED STATES PATENTS 8 Cl 11 Drawing Figures 1,582,905 5/1926 Crary 249/194 U.S. Patent Nov. 4, 1975 Sheet 1 of 2 3,917,216

Ill lll Sheet 2 of2 3,917,216

US. Patent Nov. 4, 1975 ARTICULATED CONCRETE COLUMN FORM WITH NOVEL CORNER FASTENING DEVICE The present invention relates generally to concrete column forms and has particular reference to a column form of the type which comprises specially constructed prefabricated rectangular panels which when set up for concrete-pouring operations are arranged in quadrilateral edge-to-edge relationship. The concrete column form panels with which the present invention is concerned are known in the construction field as Steel- Ply panels and are manufactured and sold by Symons Corporation of Des Plaines, lll. Steel-Ply panels in various forms are widely used in the building industry. They are assembled at the factory rather than in the field, and when shipped to a given scene of concrete building construction they are designed to be used with various articles of concrete hardware which are of special construction and permit the panels to be quickly and easily erected in'a wall form, slab form, or column form installation and subsequently removed from the installation for reuse after they have served their purpose.

A concrete form panel of the Steel-Ply type, regardless of whether it is used in connection with a wall form, a column form or a slab form, consists essentially of a shallow tray-like structure including a rectangular plywood facing the edges of which are completely encased in a rectangular metallic reinforcing frame comprising vertical or longitudinal frame members and horizontal or transverse frame members, together with a series of parallel spaced apart horizontal or transverse crossbars which extend between the vertical frame members and lend reinforcement to the medial or central region of the plywood facing by constituting a backing therefor. When such panels are set up to form a concrete column form, they are ordinarily arranged in edge-to-edge and quadrilateral relationship with adjacent plywood facings extending at a right angle to each other, outside angle bars being provided to effect the connections at the four corners of the column form.

In order to accommodate the articles of hardware which are used with Steel-Ply panels, the vertical and horizontal frame members of the reinforcing frames of the panels are provided with transverse slots, such slots being disposed ordinarily at approximately one-foot centers. When the panels are used to form a concrete column form, the aforementioned outside angle bars are provided with matching slots on one-foot centers and, when the form is set up, the vertical frame members of the reinforcing frames of adjacent panels lie flat against the adjacent flanges of the associated angle bar while T-bolt and wedge assemblies are used in connection with the registering slots in the angle bar and the adjacent vertical frame members to secure the panels in their right angular relationship on the angle bar.

A concrete column form of theaforementioned type or character is possessed of numerous limitations, principal among which is the large amount of work which is required both in setting up the form and in dismantling it. Not only is it necessary individually to handle four of the panels, thus making it expedient to employ two or more operators, but considerable time must be spent in procuring a large number of T-bolt and wedge assemabove-noted limitation that is attendant upon the construction and use of a conventional concrete column form embodying Steel-Ply panels in quadrilateral relationship and, toward this end, the invention contemplates the provision of a novel articulated concrete column form wherein, although the use of four quadrilaterally arranged panels is preserved, the form is comprised of two composite right angle sections which are hingedly or pivotally connected together in order that they are capable of being swung toward and away from each other between a closed position wherein the panels assume their quadrilateral relationship and define a rectangular void within which wet concrete may be poured for column-forming purposes, and an open position of release wherein the column form is capable of being removed laterally from the hardened concrete column. Each of the two form sections is comprised of two panels which are fixedly maintained in right angular relationship by means of a conventional angle bar. Adjacent vertical edges of the two composite form sections are maintained in contiguity by means of a pianotype hinge, the four panels thus being permanently connected together to provide the aforementioned articulated column form.

The invention is particularly concerned with a novel comer-fastening device for releasably fastening the distal vertical edges of the two composite form sections securely together to the end that the form assumed its closed condition, such comer-fastening device consisting of a conventional slotted angle bar, together with a dual T-bolt and wedge assembly including a fixed T- bolt and a shiftable T-bolt, the twobolts extending at right angles to each other and the shiftable T-bolt being movable on the fixed T-bolt between a retracted position wherein it clears one flange of the angle bar when the other fixed T-bolt is projected through one of the slots in the other flange of the angle bar, and a projected position wherein it extends through the adjacent slot in the one flange. With the movable T-bolt retracted and the fixed T-bolt projected through a slot in said other flange of the angle bar, the movable T-bolt may then be moved to its projected position wherein it enters the companion slot in said one flange, after which conventional wedge members may be driven through the usual longitudinally extending slots in the shanks of both T-bolts in order to draw the adjacent vertical frame members of the panels hard against the angle bar flanges and lock such panels in their right angle relationship, thus completing the column form. Opening of the column form is accomplished by a reversal of the operation, i.e., by withdrawing the wedges, retracting the movable T-bolt, and sliding the dual T- bolt'assembly from the column form, after which the two form sections may be swung apart to their open position for release of the form from the hardened concrete column.

In a modified form of the invention, the column form comprises three conventional Steel-Ply panels and a fourth panel which is in the form of a special column end panel, the latter being similar to a conventional panel in all respects except for the addition thereto of a slotted laterally extending flange which extends along one vertical edge of the special column end panel in the general plane of the latters plywood facing and at a right angle to the adjacent vertical frame member of the reinforcing frame of the special column end panel. This laterally extending flange, in combination with said adjacent vertical frame member, constitutes in effect an angle bar so that the use of an additional angle bar for maintaining the quadrilateral column form closed is not necessary and, instead, the vertical frame member of the adjacent column form panel is releasably secured to the laterally extending flange of the special column end panel by a single T-bolt and wedge assembly wherein the T-bolt is slidable on an anchor plate and the latter is fixedly secured by welding to the adjacent vertical frame member of the special column end panel. The modified form of the invention, therefor, employs a single T-bolt and wedge assembly in place of the aforementioned dual T-bolt and wedge assembly which is used in connection with the type of column form panel which employs four standard or conventional Steel-Ply panels.

The provision of a composite articulated concrete column form such as has briefly been outlined above and possessing the stated advantages constitutes the principal object of the present invention. Other objects and advantages, not at this time enumerated, will be come readily apparent as the nature of the invention is better understood from a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by the claims at the conclusion hereof.

In the accompanying two sheets of drawings forming a part of this specification, two illustrative embodiments of the invention are shown.

In these drawings:

FIG. 1 is a top plan view of an articulated concrete form embodying the principles of the present invention, the form embodying four identical Steel-Ply panels and being shown in its set-up or closed condition preparatory to concrete-pouring operations;

FIG. 2 is a top plan view similar to FIG. I but showing the concrete column form in its open position of release incident to removal of the form from the hard ened concrete column;

FIG. 3 is an enlarged fragmentary outside perspective view of a dual T-bolt and wedge assembly which is em ployed in connection with the embodiment of the invention illustrated in FIGS. 1 and 2 and showing the same operatively applied to the meeting edges of adjacent Steel-Ply panels which are associated with the articulated column form;

FIG. 4 is a fragmentary outside perspective view similar to FIG. 3 but showing one of two fixed connections which are effected between certain adjacent panels which are employed in connection with the concrete column form of FIGS. 1 and 2; I

FIG. 5 is a fragmentary outside perspective view similar to FIG. 4 but showing a hinged connection which is effected between certain other adjacent panels which are employed in connection with the column form of FIGS. 1 and 2;

FIG. 6 is an enlarged top perspective view of the two T-bolts of the T-bolt and wedge assembly of FIG. 3 and showing the movable T-bolt of the assembly in its projected position;

FIG. 7 is a sectional view taken on the vertical plane indicated by the line 7-7 of FIG. 6 and in the direction of the arrows;

FIG. 8 is an outside side elevational view of the structure of FIG. 6;

FIG. 9 is a bottom view of the structure of FIG. 6;

FIG. 10 is an inside side elevational view of the structure of FIG. 6; and

FIG. 11 is a perspective view similar to FIG. 3 but showing a modified column form which is made up of three identical Steel-Ply panels and a special column form end panel, only the latter panel and one adjacent regular or standard panel being illustrated.

Referring now to the drawings in detail and in particular to FIG. 1, there is disclosed in this view a composite concrete column form 10 which is comprised of four substantially identical, prefabricated, rectangular panels l2, 14, 16 and 18, the panels being so disposed as to produce a quadrilateral arrangement which defines a central rectangular void within which wet concrete may be poured in the production of a concrete column such, for example, as the column 20 of FIGS; 1 and 2. Each of the four panels is of the Steel-Ply type, is of open shallow tray-like design, and comprises a rectangular plywood facing 22 (see FIGS. 3, 4 and 5) and a marginal rectangular reinforcing frame including vertical frame members 24 and horizontal top and bottom. frame members 26. These frame members 24 and,26 are in the form of structural steel bars which are .of. shallowchannel shape in cross section. Each bar includes inside and outside outwardly extending marginal ribs 28 and 30 and a conneting base or web 32. On the side of each web that is opposite to the ribs 28 and 30 is a lateral, inwardly extending, longitudinal flange 34 on which the adjacent edge portion of the plywood facing 22 seats with its inside face flush withthetinside edges of the frame members 24 and 26. At spaced regions along the marginal ribs 28 and 30, pairs of trans versely registering notches 36 are cut and these notches, when the frame members are in contiguity with the frame members of adjacent panels, define channel voids through which the looped or slotted ends of tie rods (not shown) may pass when the panels are employed as wall form panels or when the panels are disposed in contiguity with similar panels in a column form that is designed for the production of an ex-' tremely large dimension concrete column. A rectangular, transversely extending slot 38 is formed in the web portion 32 of each frame member at the level of or in alignment with each pair of notches 36 and such slot is adapted to cooperate with a conventionalT-bolt and wedge assembly such as is disclosed in FIG. 4 and designated by the reference numeral 40 whereby the contiguous or abutting frame members of adjoining coplanar panels may be tightly drawn toward one another and maintained in clamped-together relationship. The manner in which adjacent panels may thus be connected together in coplanar relationship. and maintained spaced from similarly connected panels has been employed since the advent of such Steel-Ply panelsFor a full disclosure of the nature of a conventional Steel- Ply panel and for the use of tie rods and T-bolt and wedge assemblies for panel clamping and form side spacing purposes in connection with a concrete wall, form, reference may be had to US. Pat. No. 3,074,141, granted on Jan. 22, 1963 and entitled TIE ROD FOR CONCRETE WALL FORM PANELS. In thepresent disclosure, only suchportions of a Steel-Ply panel as are pertinent to the present concrete column form and its associated quick-release fastening devices are illus trated, these portions being illustrated only in sufficient detail as to afford an understanding of their relation to the present invention. However, the entire disclosure of such patent, insofar as it is consistent with the present disclosure. is hereby incorporated in and made a part of this patent application by reference thereto.

Referring now particularly to'FIGS. 1 and 2 of the drawings, the panels 12 and 18 of the quadrilaterally arranged series of panels are fixedly connected together as shown in FIG. 4 by means of a vertically disposed angle bar 42 which is provided with transverse slots 44 and 46 in the respective diverging flanges 48 and 50 thereof, these slots being disposed on one-foot centers so as to conform to or register with the aforementioned slots 38 in the webs 32 of the vertical frame members 24 of the adjacent panels 12 and 18. Conventional T-bolt and wedge assemblies 40 cooperate with the registering slots 38, 44 and 46 in the usual manner and serve to maintain the vertical frame members 32 of the reinforcing frames of the panels 12 and 18 in clamped relationship against the flanges 48 and 50 of the angle bar 42 so that the two panels are rigidly maintained in their right angular relationship.

The panels 14 and 16 of the column form are similarly maintained in a fixed right angular relationship by an angle bar 42 and associated T-bolt and wedge assemblies 40, the arrangement being identical to the arrangement shown in FIG 4.

The panels 12 and 14 are hingedly connected together along adjacent vertical edges by means of an elongated, vertically extending, piano-type hinge 52 (see FIG. 5) having a pair of hinge leaves 54 and 56 which are connected together for relative swinging movement by means of a vertical hinge pin 58. The leaf 54 of the piano-type hinge 52 is secured to the adjacent vertical frame member 24 of the reinforcing frame of the panel 14 by means of T-bolt and wedge assemblies 40, while the leaf 56 of the hinge 52 is similarly secured to the adjacent vertical frame member 24 of the reinforcing frame of the panel 12.

From the above description, it will be apparent that with the panels 12 and 18 rigidly connected together in right angle relationship, and the panels 14 and 16 similarly secured together, the hinge connection between the panels 12 and 14 establishes a column form which is, in effect, comprised of two angular components 60 and 62 (see FIGS. 1 and 2) which are capable of swinging movement toward and away from each other between a closed column form Lti'tditlOIl as shown in FIG. 1 and an open column form condition as shown in FIG. 2. In the closed condition of the column form 10, the quadrilateral panel arrangement of FIG. 1 obtains wherein the four panels define a void within which wet concrete is adapted to be poured in the formation of a column such as the column of FIGS. 1 and 2. After the poured concrete has become set or hardened, the two right angle sections of the column form 10 may be swung apart as shown in FIG. 2, thus releasing the form from the column 20 and allowing such form to be transported to another location for reuse thereof.

One of the principal features of the present invention resides in the provision of a novel comer fastening device such as is illustrated in FIGS. 3 and 6 to 10, inclusive, and by means of which the distal end edges of the two column form sections 60 and 62 may be secured together when the form as a whole is in its closed condition and quickly released in order to permit opening of such form to release the hardened concrete column 20. In effect, this fastening device, which is designated in its entirety by the reference numeral 70 in FIG. 5, consists of two specially designed T-bolts, namely, a principal or main T-bolt 72 and a secondary T-bolt 74. It is, of course, to be understood that there will be several of the fastening devices 70 in order releasably to maintain 6 the form 10 in its closed condition for concrete-receiving purposes.

The T-bolt 72 of the fastening device is comprised of a generally rectangular plate portion 76 from which there projects forwardly a shank portion 78. As best seen in FIGS. 3, 6 and 8 of the drawings, the plate portion 76 is provided with a downwardly offset section 80 which is connected to the main body of the plate portion by an inclined section 82. The shank portion of the T-bolt 72 is formed integrally with and projects forwards from the offset section of the plate portion 76 and has formed therein a longitudinally extending slot 84 for receiving a conventional wedge 85 like the wedge part of any of the aforementioned assemblies 40.

As shown in FIG. 3, the plate portion 76 of the T-bolt 72 has formed therein a small hole 83, such hole serving as an attachment point for an S-shaped connecting element on one end of a flexible chain 85, the latter being connected at its other end by an S-shaped connecting element to a similar attachment hole 87 in the large end of a conventional generally triangular wedge piece 89. The latter is designed for cooperation with the T-bolt 74 for clamping purposes as will be subsequently described.

The T-bolt 74 of the comer fastening device 10 is comprised of a body portion 86 and a reduced coplanar shank portion 88, the latter being provided with a longitudinally extending slot 90 (see FIGS. 6, 7 and 8) for receiving the wedge 89. Said T-bolt 74 is slidable on the plate portion 76 of the T-bolt 72 in a transverse direction with respect to the T-bolt 72 but in a longitudinal direction with respect to itself. Accordingly, the body portion 86 of the T-bolt 74 has formed therein a longitudinal slot 92 (see FIGS. 7 and 9) while a shouldered stud 94 passes through the slot 92 and is provided at one end with an enlarged retaining head 96 which underlies the body portion 86 of the T-bolt 74. The other endof the stud has a flattened or rivet-like part 98 (see also FIGS. 6 and 10) by means of which the stud as a whole is secured to the T-bolt 72. The end of the body portion 86 which is remote from the reduced shank portion 88 is bentdownwards in order to form a striking flange 100 for a purpose that will be set forth subsequently.

The T-bolt 74-of the corner fastening device 70 is slidable on the T-bolt 72 between a retracted position as shown in dotted lines in FIGS. 3 and 9, and a fully projected position as shown in full lines in these views and also in FIGS. 7 and 10. It is to be noted that when the T-bolt 74 is in its retracted position, the distal or forward end of the shank portion 88 thereof lies slightly within the confines of the plate portion 76 of the T-bolt 72 or is at least coincident with the adjacent edge of such plate portion for panel clearance purposes as will be made clear presently. It is also to be noted that the inclined section 82 of the T-bolt 72 extends alongside the body portion 86 of the T-bolt 74 and thus constitutes a guide means for preventing relative angular turning movement between the two T-bolts.

The aforementioned dual T'bolt and wedge assembly 70 with like assemblies is used in connection with an angle bar like the angle bar 42 which is used between the adjacent side edges of the panels 12 and 18 and the angle bar which is used between the panels 14 and 16. For expediency, the angle bar which is used in connection with the assembly 70 has applied to it the same reference numerals as those that are applied to the previously mentioned angle bars 42. As best shown in FIG.

3 of the drawings, the angle bar 42 which is used in connection with the dual T-bolt and wedge assembly 70 comprises right angle flanges 48 and 50. The flange 48 fits against the vertical frame member 24 of the reinforcing frame of the panel 18 and has transversely extending slots 44 in register with the slots 38 in said adjacent vertical frame member 24. The other flange of the angle bar 42 which is used in connection with the cor ner fastening device 70 fits against the adjacent vertical frame member 24 of the reinforcing frame of the panel 16 and has transverse slots 46. When the fastening device 70 is in its operative position as illustrated in FIG. 3, the shank portion 78 of the main T-bolt 72 extends through one of the slots 42 in the flange 48 and the adjacent slot 38 in the adjacent vertical frame member 24 and when the wedge 85 is driven into place through the slot 84 in the shank portion 78 the bolt 72 is clamped in fixed relation with the associated parts, namely, the flange 48 and the adjacent vertical frame member 24 of the reinforcing frame of the panel 18. Also when the fastening device 70 is in its operative position, the T- bolt 74, while in its projected position, extends through the slot 46 in the flange 50 of the associated angle bar 42 and also the slot 38 in the vertical frame member 24 of the reinforcing frame of the panel 16 and after driving the wedge 89 downwards through the slot in the shank portion of the T-bolt 72 serves to maintain in clamped relationship the aforementioned flange 46 and the last-mentioned vertical frame member 24.

From the above description, it will be apparent that by utilizing four identical standard Steel-Ply panels such as the panels 12, l4, l6 and 18, three angle bars 42, one piano-type hinge 52, and an appropriate number of the fastening bolt assemblies 70, depending upon the height of the various panels, the present articulated column form may readily be assembled for protracted use in the creation of successive concrete columns such as the column 20. Assembly of the form 10 is accomplished by selecting two pairs of panels and fixedly securing the panels of each pair in their proper right angular relationship in the manner set forth previously in connection with FIG. 4 by utilizing an angle bar 42 and T-bolt and wedge assemblies 40 for this purpose. Such pairing and uniting of panels results in the creation of the form sections 60 and 62 (see FIGS. 1 and 2) of the column form 10. Thereafter, one leaf of the piano-type hinge 52 is secured by T-bolt and wedge assemblies 40 to one vertical frame member 24 of one of the panels of the section 60 and the other leaf is secured to the adjacent vertical frame member 24 of the section 62, again utilizing T-bolt and wedge assemblies 40 for securing purposes as shown in FIG. 5. The final step in assembling the concrete column form 10 consists in the application of one of the angle bars 42 to the vertical frame member 24 at the distal side edge of either of the two form sections 60 and 62. It is immaterial which distal side edge is selected and, assuming for descriptive puposes that such angle bar 42 is to be applied to the vertical frame member 24 at the distal side edge of the panel 18, the flange 48 of the angle bar is applied to said vertical frame member so that the slots 44 therein register with the slots 38 in the adjacent vertical frame member of the reinforcing frame of the panel 18. After such registry of slots has been effected, two or more of the fastening bolt assemblies 70 are successively applied to the pairs of registering slots at different elevations so as to anchor the associated angle bar 42 to the adjacent vertical frame member 24.

Application of each fastening device to its associ-1 ated registering slots 44 and 38 is effected by the simple expedient of projecting the forwardly extending shank portions 78 through both slots until the forward edge of the downwardly offset section 80 of the T-bolt 72 abuts against the adjacent face of the flange 48 as shown in FIG. 3. Thereafter, a wedge is driven downwardly through the slot 84 in the shank portion 78, thus drawing the offset section 80 hard against the outer face of the flange 48 and securing the T-bolt 72 firmly in position on such flange as well as firmly clamping said flange 48 against the adjacent vertical frame member of the panel 18. The application of the requisite number of fastening devices 70 to the flange 48 completes connection of the flange 48 of the associated angle bar to the distal side edge of the panel 18.

In order to set up the thus partially assembled column form 10 at the desired location where a concrete column is to be constructed, the form is transported to such location, set on edge and the two form sections 60 I and 62 are then swung to their closed position wherein tening device 70 is maintained in its retracted position and, as soon as the distal frame member 24 of the panel 16 is in engagement with the flange 50, the shank portion 88 of the shiftable T-bolt 74 is caused to project 1 through the registering slots 44 and 38, after which the triangular wedge piece 89 is driven downwardly through the slot 90 in the shank portion 88 in order to effect firm clamping of the distal vertical frame member 32 of the panel 16 against the flange 50 of the associated angle bar 42 and resultant locking of the two form sections 60 and 62 in their closed position. The downtumed flange on the body portion 86 of the T-bolt 74 establishes a striking surface whereby said T- bolt may be driven to its home position or, alternatively, it may be withdrawn from the slots 44 and 38 at such time as the fastening device 70 is released. When all of the shiftable T-bolts 74 of the fastening devices 70 are driven to their home positions with the wedges 89 in place, the two sections 60 and 62 of the column form 10 are securely locked in their closedpositions and concrete-pouring operations may then be undertaken with the view of effecting formation of the .col-.

umn.

After the concrete has been poured into the interior of the closed form 10 and the concrete has become set, release of the form from the column 20 is accomplished by withdrawing the shiftable T-bolts from the adjacent slots 44 and 38 by first removing the wedges 89 and then striking the downtumed flanges 74 to retract the, I

gether with three angle bars. The three standard panels correspond structurally and positionally to the panels 12, 14 and 16 of the column form 10 while the end panel corresponds positionally to the panel l8. The disclosure of FIG. 11 is a fragmentary one and the two hingedly-connected panels which correspond to the panels 14 and 16 have not been disclosed in this view. Because of the similarity between the concrete column form 110 and the previously described concrete column form 10, similar reference numerals but of a higher order have been applied to the corresponding parts as between the disclosure of FIGS. 11 and 3 in order to avoid needless repetition of description.

Referring now to FIG. 11 in detail, the column form end panel 118 is similar in many respects to a standard Steel-Ply panel except for the fact that the bolt-receiving slots 38 in the distal vertical frame member 124 are omitted while a laterally extending slotted attachment flange 150 is integrally formed with the adjacent vertical frame member of the reinforcing frame of the special form and panel 118 and lies in coplanar relationship with respect to the plywood facing 122 of said panel 118. The attachment flange 150 extends at a right angle to the adjacent vertical frame member 124 of the panel 118 and thus the flange 150 and said vertical frame member of the panel 118 correspond to the angle bars 42 which are employed between the panels 16 and 18 of the concrete column form 10. Stated oth-.

erwise, and by comparing the structure of FIG. '11 with ated angle bar 42 instead of with the flange 48. Additionally, by inverting the fastening assembly 70, the position of the T-bolts 72 and 74 may be reversed with respect to the associated registering pairs of slots 44 and 38 and the device 70 will still function in a satisfactory manner releasably to maintain the hinged-together sections of the column form 10 in their closed condition, although from the point of view of the operator, applications of the inverted fastening device to and removal thereof from the column form 10 may be less facile. Therefore, only insofar as the invention is particularly pointed out in the accompanying claims is the same to be limited.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a concrete form of the type that comprises a series of upstanding rectangular panels two of which are in contiguous relationship, extend at a right angle to each other and have along their adjacent side edges outwardly extending flange-like members which extend at a right angle to each other and have transverse slots therein at substantially the same level, the improvement which comprises a fastening device adapted releasably to retain the two panels in their normal posithe structure of FIG. 3, the attachment flange 150 bears the same positional relationship in the column form 10 as does the flange 50 of the angle bar 42, while the distal vertical frame member 124 of the panel 118 bears the same positional relationship as does theflange 48 of the angle bar 42 between the panels 16 and 18 of the column form 10. Because of this similarity in position, it is unnecessary to employ a separate angle bar and closing movements of the two column form sections 160 and 162 are completed when the distal vertical frame member 124 of the panel 16 is brought against the attachment flange 150 so that the slots in the distal frame member of the panel 1 l6 and the slots 146 in the attracting flange 150 move intoregister with one another. g

The fastening device 170 which with similar devices is used for releasably securing the two panels 118 and tion of contiguity and comprising a first T-bolt embodying a plate-like body portion at one end thereof and a reduced longitudinally slotted shank at its other end,

- and having its body portion disposed in the space beit is slidable transversely thereon, and adapted when so slid in a direction normal to the other flange-like member to have its shank portion extend through the slot in said other flange-like member, and wedge pieces projecting through the longitudinally extending slots in the shank portions of the two T-bolts and serving when 116' together in their right angular edge-to-edge 'relationship is similar to the aforementioned fastening device 70 except for the fact that the T-bolt 72 of the,de-'

on the distal frame member 124 of the reinforcing frame of the panel 18 as a permanent component or part of said panel. Otherwise, the fastening device 170 remains substantialy the same as the fastening device 70.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. Neither is the invention to be limited to the precise mode of assembly of the various constituent panels and other components which have been set forth herein. For example, by constructing a mirror-image of the fastening device 70, the primary T-bolt 72 may be driven into place to draw the body portions of said T- g I boltshard against their respective flange-like members.

' claim -1- and whereinthe plate-like body portion of the and thus, the fastening device 170 remains in position first T-bolt is provided with an offset portion which lies in the general plane of the body portion of the second T-bolt and establishes guide means for preventing relative turning movement between the two T-bolts.

3. In -an articulated concrete form, a series of substantially identical vertically disposedpanels arranged I in quadrilateral relationship so as to define therebecaused to cooperate with the flange 50 of the associtween an enclosed rectangular void into which wet concrete may be poured to produce a vertical column,

each panel being comprised of a rectangular facing bounded by a marginal reinforcing frame including opposed vertical frame members and opposed horizontal frame members which project laterally from the general plane of the panel facing in the same direction, thus defining a shallow tray-like structure, each of said 'vertical frame members being formed with a row of means hingedly connecting together the contiguous vertical frame members of adjacent panels at a third corner of the void, thus defining rigid and angular column form sections which are capable of swinging movement bodily toward and away from each other between a normal closed column-confining quadrilateral condition and an open position of column release, a third angle bar having flanges fitting adjacent vertical frame members at said fourth corner of the void, said flanges being formed with slots which register with the slots in such adjacent vertical frame members, and a removable unitary fastening device for securing said third angle bar to said adjacent vertical frame members, said fastening device including a first T-bolt having a body portion and a reduced narrow tongue-like shank portion removably projecting through a pair of registering slots in one flange of the third angle bar and the adjacent vertical frame members, a second T-bolt slidable on said first T-bolt in and transversely of said tongue-like shank portion and also having a body portion and a shank portion removably projecting through a pair of registering slots in the other flange of the third angle bar and the adjacent vertical frame members, said tongue-like shank portions extending at a right angle to each other, wedge pieces removably projecting through the slots in said shank portions and serving to draw the body portions of the respective T-bolts hard against their associated angle bar flanges, and coacting guide means on said T-bolts for preventing relative turning movement therebetween.

4. An articulated concrete column form as set forth in claim 1 and wherein said second T-bolt underlies the first T-bolt and is provided with a longitudinal slot in the body portion thereof, and a headed stud projects through said slot in the body portion of the second T- bolt and is anchored to the body portion of the first T- bolt.

5. An articulated concrete column form as set forth in claim 4 and wherein the body portion of the first T- bolt is formed with an offset section which lies in the general plane of the second T-bolt and establishes said guide means for preventing relative turning movement between the T-bolts.

6. An articulated concrete column form as set forth in claim 5 and wherein the end of the body portion of the second T-bolt that is remote from the shank portion of said second T-bolt is provided with a downturned striking flange.

ous vertical frame members of adjacent panels at each j of one pair of diagonally opposed corners of the rectangular void, means hingedly connecting together the contiguous vertical frame members of adjacent panels at a third comer of the void, thus defining two rigid and angular column form sections which are capable of swinging movement toward and away from each other between a normal closed column-confining quadrilateral condition and anopen position of column release, one of the vertical frame members at the fourth corner of the void and at a region diagonally disposed with respect to said hingedly connecting means in the form of an anglepiece having a first attachment flange which lies in the general plane-of the facing of the associated panel and a second flange which extends at a right angle to such facing, said first flange being provided with a series of vertically spaced slots which register withcorresponding slots in the adjacent vertical frame members, a plate-like body fixedly secured to said second flange of the anglepiece and positioned approximately at the level of one of the slots in said first flange of the anglepiece, an elongated T-bolt embodying a body portion at one end and a reduced longitudinally slotted shank at its other end and having its body portion provided with a longitudinal slot, a headed stud on said body and projecting through said longitudinal slot thus forming a sliding connection between the T bolt and plate-like body, and a wedge projecting through;

the slot in the shank portion of the T-bolt and serving when driven into place to draw the body portion of the 4 8. An articulated concrete column form as set forth in claim 7 and wherein the end of the body portion of the T-bolt remote from the shank portionithereof is provided with a downturned striking flange. 

1. In a concrete form of the type that comprises a series of upstanding rectangular panels two of which are in contiguous relationship, extend at a right angle to each other and have along their adjacent side edges outwardly extending flange-like members which extend at a right angle to each other and have transverse slots therein at substantially the same level, the improvement which comprises a fastening device adapted releasably to retain the two panels in their normal position of contiguity and comprising a first T-bolt embodying a plate-like body portion at one end thereof and a reduced longitudinally slotted shank at its other end, and having its body portion disposed in the space between the two flange-like members and abutting against one of said flange-like members and its shank portion extending through and beyond the transverse slot in said one flange-like member, an elongated second T-bolt embodying a body portion at one end thereof and a reduced longitudinally slotted shank portion at its other end, having its body portion slidably connected to the body portion of the first T-bolt so that it is slidable transversely thereon, and adapted when so slid in a direction normal to the other flange-like member to have its shank portion extend through the slot in said other flange-like member, and wedge pieces projecting through the longitudinally extending slots in the shank portions of the two T-bolts and serving when driven into place to draw the body portions of said T-bolts hard against their respective flange-like members.
 2. In a concrete form, the improvement set forth in claim 1 and wherein the plate-like body portion of the first T-bolt is provided with an offset portion which lies in the general plane of the body portion of the second T-bolt and establishes guide means for preventing relative turning movement between the two T-bolts.
 3. In an articulated concrete form, a series of substantially identical vertically disposed panels arranged in quadrilateral relationship so as to define therebetween an enclosed rectangular void into which wet concrete may be poured to produce a vertical column, each panel being comprised of a rectangular facing bounded by a marginal reinforcing frame incluDing opposed vertical frame members and opposed horizontal frame members which project laterally from the general plane of the panel facing in the same direction, thus defining a shallow tray-like structure, each of said vertical frame members being formed with a row of vertical spaced apart horizontally elongated slots therein, an angle bar fixedly secured to the vertical frame members of adjacent panels at each of one pair of diagonally opposed corners of the rectangular void and serving to maintain such adjacent panels in their right angular relationship and positions of contiguity, means hingedly connecting together the contiguous vertical frame members of adjacent panels at a third corner of the void, thus defining rigid and angular column form sections which are capable of swinging movement bodily toward and away from each other between a normal closed column-confining quadrilateral condition and an open position of column release, a third angle bar having flanges fitting adjacent vertical frame members at said fourth corner of the void, said flanges being formed with slots which register with the slots in such adjacent vertical frame members, and a removable unitary fastening device for securing said third angle bar to said adjacent vertical frame members, said fastening device including a first T-bolt having a body portion and a reduced narrow tongue-like shank portion removably projecting through a pair of registering slots in one flange of the third angle bar and the adjacent vertical frame members, a second T-bolt slidable on said first T-bolt in and transversely of said tongue-like shank portion and also having a body portion and a shank portion removably projecting through a pair of registering slots in the other flange of the third angle bar and the adjacent vertical frame members, said tongue-like shank portions extending at a right angle to each other, wedge pieces removably projecting through the slots in said shank portions and serving to draw the body portions of the respective T-bolts hard against their associated angle bar flanges, and coacting guide means on said T-bolts for preventing relative turning movement therebetween.
 4. An articulated concrete column form as set forth in claim 1 and wherein said second T-bolt underlies the first T-bolt and is provided with a longitudinal slot in the body portion thereof, and a headed stud projects through said slot in the body portion of the second T-bolt and is anchored to the body portion of the first T-bolt.
 5. An articulated concrete column form as set forth in claim 4 and wherein the body portion of the first T-bolt is formed with an offset section which lies in the general plane of the second T-bolt and establishes said guide means for preventing relative turning movement between the T-bolts.
 6. An articulated concrete column form as set forth in claim 5 and wherein the end of the body portion of the second T-bolt that is remote from the shank portion of said second T-bolt is provided with a downturned striking flange.
 7. In an articulated concrete column form, a series of vertically disposed panels arranged in quadrilateral relationship so as to define therebetween an enclosed rectangular void into which wet concrete may be poured to produce a vertical column, each panel being comprised of a rectangular facing bounded by a marginal frame including opposed vertical frame members and opposed horizontal frame members which project laterally from the general plane of the plywood facing in the same direction, thus defining a shallow tray-like structure, means fixedly securing together the contiguous vertical frame members of adjacent panels at each of one pair of diagonally opposed corners of the rectangular void, means hingedly connecting together the contiguous vertical frame members of adjacent panels at a third corner of the void, thus defining two rigid and angular column form sections which are capable of swinging movement toward and away from each other between a normal Closed column-confining quadrilateral condition and an open position of column release, one of the vertical frame members at the fourth corner of the void and at a region diagonally disposed with respect to said hingedly connecting means in the form of an anglepiece having a first attachment flange which lies in the general plane of the facing of the associated panel and a second flange which extends at a right angle to such facing, said first flange being provided with a series of vertically spaced slots which register with corresponding slots in the adjacent vertical frame members, a plate-like body fixedly secured to said second flange of the anglepiece and positioned approximately at the level of one of the slots in said first flange of the anglepiece, an elongated T-bolt embodying a body portion at one end and a reduced longitudinally slotted shank at its other end and having its body portion provided with a longitudinal slot, a headed stud on said body and projecting through said longitudinal slot thus forming a sliding connection between the T-bolt and plate-like body, and a wedge projecting through the slot in the shank portion of the T-bolt and serving when driven into place to draw the body portion of the T-bolt hard against said first flange to thus clamp said latter flange to the adjacent vertical frame member at the fourth corner of the void.
 8. An articulated concrete column form as set forth in claim 7 and wherein the end of the body portion of the T-bolt remote from the shank portion thereof is provided with a downturned striking flange. 